Percy a



P. A. BOECK.

ROTARY KILN.

APPLlcATloN FILED APn.2a.1911.

Patented Aug. 26, 1919.

A TTORNEYS HIM WIT/VESSES PERCY A. BOECK, 0F NEW YORK, N. Y. y

ROTARY KILN.

Specification of Letters Patent.

y Patented Allg. 26, 1919.

Application led April 28, 1917. Serial No. 165,295.

i To all whom z't may concern:

y through the refractory wall of the kiln and to increase the capacity of the kiln, thereby obtaining a more economical kiln.

Another object of the invention is to provide a kiln so insulated as to prevent injury to the shell of the kiln by the heat generated within.

A still further object of the invention is to provide a kiln so insulated as to prevent excessive heating in the maximum temperature zone.

I attain these and other objects of my invention by the structure conventionally disclosed in the accompanying drawings,

wherein similar characters of reference indicate corresponding parts in both views.

Figure 1 is a longitudinal section of a rotary cement kiln embodying my invention; and

Fig. 2 is a cross section thereof. Referring to the drawings, 3 is the shell or housing of the kiln, which is lined with refractory material forming a wall or lining 4. In the maximum temperature zone the lining is in direct contact with the shell. In the lower temperature zones the lining 4 is insulated from the shell by kieselguhr 5, preferably in the shape of bricks, which has a lower heat conductivity than the refractory material. The kieselguhr filling increases the interior temperature of the lower temperature zones by preventing heat radiation. It also protects the shell from the high temperature to which the lining is subjected. The result is a higher temperature within the kiln in the lower zone and more uniform. This increases the capacity of the kiln as it permits a higher velocity of the material to be heated, in consequence increasing the efliciency of the kiln. By reducing the heat radiation, there is an economy of fuel.

I claim: l

1. A rotary kiln comprising a shell, a refractory lining therein, and a filler of kieselguhr between the shell and lining from the highest temperature zone to and including the lowest temperature zone. Y

2. A rotary kiln comprising a Shell, a re fractory lining therein, and kieselguhr bricks between the lining and shell extending from the highest temperature zone of the kiln to and including the lowest temperature zone.

PERCY A. BOECK. 

